<template>
	<view class="u-checkbox" :style="[checkboxStyle]" @tap.stop="wrapperClickHandler"
		:class="[`u-checkbox-label--${parentData.iconPlacement}`, parentData.borderBottom && parentData.placement === 'column' && 'u-border-bottom']">
		<view class="u-checkbox__icon-wrap" @tap.stop="iconClickHandler" :class="iconClasses" :style="[iconWrapStyle]">
			<slot name="icon">
				<u-icon class="u-checkbox__icon-wrap__icon" name="checkbox-mark" :size="elIconSize" :color="elIconColor" />
			</slot>
		</view>
		<view @tap.stop="labelClickHandler">
			<slot name="label">

				<text  :style="{
					color: elDisabled ? elInactiveColor : elLabelColor,
					fontSize: elLabelSize,
					lineHeight: elLabelSize
				}">{{ label }}</text>
			</slot>
		</view>


	</view>
</template>

<script>
import props from './props.js';
import mpMixin from '../../libs/mixin/mpMixin.js';
import mixin from '../../libs/mixin/mixin.js';
/**
 * checkbox  复选框
 * @description 复选框组件一般用于需要多个选择的场景，该组件功能完整，使用方便
 * @tutorial https://uviewui.com/components/checkbox.html
 * @property {String | Number | Boolean}	name			checkbox组件的标示符
 * @property {String}						shape			形状，square为方形，circle为圆型
 * @property {String | Number}				size			整体的大小
 * @property {Boolean}						checked			是否默认选中
 * @property {String | Boolean}				disabled		是否禁用
 * @property {String}						activeColor		选中状态下的颜色，如设置此值，将会覆盖parent的activeColor值
 * @property {String}						inactiveColor	未选中的颜色
 * @property {String | Number}				iconSize		图标的大小，单位px
 * @property {String}						iconColor		图标颜色
 * @property {String | Number}				label			label提示文字，因为nvue下，直接slot进来的文字，由于特殊的结构，无法修改样式
 * @property {String}						labelColor 		label的颜色
 * @property {String | Number}				labelSize		label的字体大小，px单位
 * @property {String | Boolean}				labelDisabled	是否禁止点击提示语选中复选框
 * @property {Object}						customStyle		定义需要用到的外部样式
 * 
 * @event {Function}	change	任一个checkbox状态发生变化时触发，回调为一个对象
 * @example <u-checkbox v-model="checked" :disabled="false">天涯</u-checkbox>
 */
export default {
	name: "u-checkbox",
	mixins: [mpMixin, mixin, props],
	data () {
		return {
			isChecked: false,
			// 父组件的默认值，因为头条小程序不支持在computed中使用this.parent.shape的形式
			// 故只能使用如此方法
			parentData: {
				iconSize: 12,
				labelDisabled: null,
				disabled: null,
				shape: 'square',
				activeColor: null,
				inactiveColor: null,
				size: 18,
				// #ifdef VUE2
				value: null,
				// #endif
				// #ifdef VUE3
				modelValue: null,
				// #endif
				iconColor: null,
				placement: 'row',
				borderBottom: false,
				iconPlacement: 'left'
			}
		}
	},
	computed: {
		// 是否禁用，如果父组件u-raios-group禁用的话，将会忽略子组件的配置
		elDisabled () {
			return this.disabled !== '' ? this.disabled : this.parentData.disabled !== null ? this.parentData.disabled : false;
		},
		// 是否禁用label点击
		elLabelDisabled () {
			return this.labelDisabled !== '' ? this.labelDisabled : this.parentData.labelDisabled !== null ? this.parentData.labelDisabled :
				false;
		},
		// 组件尺寸，对应size的值，默认值为21px
		elSize () {
			return this.size ? this.size : (this.parentData.size ? this.parentData.size : 21);
		},
		// 组件的勾选图标的尺寸，默认12px
		elIconSize () {
			return this.iconSize ? this.iconSize : (this.parentData.iconSize ? this.parentData.iconSize : 12);
		},
		// 组件选中激活时的颜色
		elActiveColor () {
			return this.activeColor ? this.activeColor : (this.parentData.activeColor ? this.parentData.activeColor : '#2979ff');
		},
		// 组件选未中激活时的颜色
		elInactiveColor () {
			return this.inactiveColor ? this.inactiveColor : (this.parentData.inactiveColor ? this.parentData.inactiveColor :
				'#c8c9cc');
		},
		// label的颜色
		elLabelColor () {
			return this.labelColor ? this.labelColor : (this.parentData.labelColor ? this.parentData.labelColor : '#606266')
		},
		// 组件的形状
		elShape () {
			return this.shape ? this.shape : (this.parentData.shape ? this.parentData.shape : 'circle');
		},
		// label大小
		elLabelSize () {
			return uni.$u.addUnit(this.labelSize ? this.labelSize : (this.parentData.labelSize ? this.parentData.labelSize :
				'15'))
		},
		elIconColor () {
			const iconColor = this.iconColor ? this.iconColor : (this.parentData.iconColor ? this.parentData.iconColor :
				'#ffffff');
			// 图标的颜色
			if (this.elDisabled) {
				// disabled状态下，已勾选的checkbox图标改为elInactiveColor
				return this.isChecked ? this.elInactiveColor : 'transparent'
			} else {
				return this.isChecked ? iconColor : 'transparent'
			}
		},
		iconClasses () {
			let classes = []
			// 组件的形状
			classes.push('u-checkbox__icon-wrap--' + this.elShape)
			if (this.elDisabled) {
				classes.push('u-checkbox__icon-wrap--disabled')
			}
			if (this.isChecked && this.elDisabled) {
				classes.push('u-checkbox__icon-wrap--disabled--checked')
			}
			// 支付宝，头条小程序无法动态绑定一个数组类名，否则解析出来的结果会带有","，而导致失效
			// #ifdef MP-ALIPAY || MP-TOUTIAO
			classes = classes.join(' ')
			// #endif
			return classes
		},
		iconWrapStyle () {
			// checkbox的整体样式
			const style = {}
			style.backgroundColor = this.isChecked && !this.elDisabled ? this.elActiveColor : '#ffffff'
			style.borderColor = this.isChecked && !this.elDisabled ? this.elActiveColor : this.elInactiveColor
			style.width = uni.$u.addUnit(this.elSize)
			style.height = uni.$u.addUnit(this.elSize)
			// 如果是图标在右边的话，移除它的右边距
			if (this.parentData.iconPlacement === 'right') {
				style.marginRight = 0
			}
			return style
		},
		checkboxStyle () {
			const style = {}
			if (this.parentData.borderBottom && this.parentData.placement === 'row') {
				uni.$u.error('检测到您将borderBottom设置为true，需要同时将u-checkbox-group的placement设置为column才有效')
			}
			// 当父组件设置了显示下边框并且排列形式为纵向时，给内容和边框之间加上一定间隔
			if (this.parentData.borderBottom && this.parentData.placement === 'column') {
				style.paddingBottom = '8px'
			}
			return uni.$u.deepMerge(style, uni.$u.addStyle(this.customStyle))
		}
	},
	mounted () {
		this.init()
	},
	methods: {
		init () {
			// 支付宝小程序不支持provide/inject，所以使用这个方法获取整个父组件，在created定义，避免循环引用
			this.updateParentData()
			if (!this.parent) {
				uni.$u.error('u-checkbox必须搭配u-checkbox-group组件使用')
			}
			// #ifdef VUE2
			const value = this.parentData.value
			// #endif
			// #ifdef VUE3
			const value = this.parentData.modelValue
			// #endif
			// 设置初始化时，是否默认选中的状态，父组件u-checkbox-group的value可能是array，所以额外判断
			if (this.checked) {
				this.isChecked = true
			} else if (uni.$u.test.array(value)) {
				// 查找数组是是否存在this.name元素值
				this.isChecked = value.some(item => {
					return item === this.name
				})
			}
		},
		updateParentData () {
			this.getParentData('u-checkbox-group')
		},
		// 横向两端排列时，点击组件即可触发选中事件
		wrapperClickHandler (e) {
			this.parentData.iconPlacement === 'right' && this.iconClickHandler(e)
		},
		// 点击图标
		iconClickHandler (e) {
			this.preventEvent(e)
			// 如果整体被禁用，不允许被点击
			if (!this.elDisabled) {
				this.setRadioCheckedStatus()
			}
		},
		// 点击label
		labelClickHandler (e) {
			this.preventEvent(e)
			// 如果按钮整体被禁用或者label被禁用，则不允许点击文字修改状态
			if (!this.elLabelDisabled && !this.elDisabled) {
				this.setRadioCheckedStatus()
			}
		},
		emitEvent () {
			this.$emit('change', this.isChecked)
			// 尝试调用u-form的验证方法，进行一定延迟，否则微信小程序更新可能会不及时
			this.$nextTick(() => {
				uni.$u.formValidate(this, 'change')
			})
		},
		// 改变组件选中状态
		// 这里的改变的依据是，更改本组件的checked值为true，同时通过父组件遍历所有u-checkbox实例
		// 将本组件外的其他u-checkbox的checked都设置为false(都被取消选中状态)，因而只剩下一个为选中状态
		setRadioCheckedStatus () {
			// 将本组件标记为与原来相反的状态
			this.isChecked = !this.isChecked
			this.emitEvent()
			typeof this.parent.unCheckedOther === 'function' && this.parent.unCheckedOther(this)
		}
	},
	watch: {
		checked () {
			this.isChecked = this.checked
		}
	}
}
</script>

<style lang="scss" scoped>
@import "../../libs/css/components.scss";
$u-checkbox-icon-wrap-margin-right: 6px !default;
$u-checkbox-icon-wrap-font-size: 6px !default;
$u-checkbox-icon-wrap-border-width: 1px !default;
$u-checkbox-icon-wrap-border-color: #c8c9cc !default;
$u-checkbox-icon-wrap-icon-line-height: 0 !default;
$u-checkbox-icon-wrap-circle-border-radius: 100% !default;
$u-checkbox-icon-wrap-square-border-radius: 3px !default;
$u-checkbox-icon-wrap-checked-color: #fff !default;
$u-checkbox-icon-wrap-checked-background-color: red !default;
$u-checkbox-icon-wrap-checked-border-color: #2979ff !default;
$u-checkbox-icon-wrap-disabled-background-color: #ebedf0 !default;
$u-checkbox-icon-wrap-disabled-checked-color: #c8c9cc !default;
$u-checkbox-label-margin-left: 5px !default;
$u-checkbox-label-margin-right: 12px !default;
$u-checkbox-label-color: $u-content-color !default;
$u-checkbox-label-font-size: 15px !default;
$u-checkbox-label-disabled-color: #c8c9cc !default;

.u-checkbox {
	/* #ifndef APP-NVUE */
	@include flex(row);
	/* #endif */
	overflow: hidden;
	flex-direction: row;
	align-items: center;
	margin-bottom: 5px;
	margin-top: 5px;

	&-label--left {
		flex-direction: row
	}

	&-label--right {
		flex-direction: row-reverse;
		justify-content: space-between
	}

	&__icon-wrap {
		/* #ifndef APP-NVUE */
		box-sizing: border-box;
		// nvue下，border-color过渡有问题
		transition-property: border-color, background-color, color;
		transition-duration: 0.2s;
		/* #endif */
		color: $u-content-color;
		@include flex;
		align-items: center;
		justify-content: center;
		color: transparent;
		text-align: center;
		margin-right: $u-checkbox-icon-wrap-margin-right;

		font-size: $u-checkbox-icon-wrap-font-size;
		border-width: $u-checkbox-icon-wrap-border-width;
		border-color: $u-checkbox-icon-wrap-border-color;
		border-style: solid;

		/* #ifdef MP-TOUTIAO */
		// 头条小程序兼容性问题，需要设置行高为0，否则图标偏下
		&__icon {
			line-height: $u-checkbox-icon-wrap-icon-line-height;
		}

		/* #endif */

		&--circle {
			border-radius: $u-checkbox-icon-wrap-circle-border-radius;
		}

		&--square {
			border-radius: $u-checkbox-icon-wrap-square-border-radius;
		}

		&--checked {
			color: $u-checkbox-icon-wrap-checked-color;
			background-color: $u-checkbox-icon-wrap-checked-background-color;
			border-color: $u-checkbox-icon-wrap-checked-border-color;
		}

		&--disabled {
			background-color: $u-checkbox-icon-wrap-disabled-background-color !important;
		}

		&--disabled--checked {
			color: $u-checkbox-icon-wrap-disabled-checked-color !important;
		}
	}

	&__label {
		/* #ifndef APP-NVUE */
		word-wrap: break-word;
		/* #endif */
		margin-left: $u-checkbox-label-margin-left;
		margin-right: $u-checkbox-label-margin-right;
		color: $u-checkbox-label-color;
		font-size: $u-checkbox-label-font-size;

		&--disabled {
			color: $u-checkbox-label-disabled-color;
		}
	}
}
</style>